Switching GLP-1 medications: Ozempic to Mounjaro, Wegovy to Zepbound, or a shot to a pill

Can you switch between GLP-1 medications?

Yes. People move between GLP-1 medicines for many reasons: insurance or cost, supply problems, side effects, not enough effect, a wish for a weekly shot instead of a daily pill (or the reverse), or a heart-protection benefit their doctor wants. A 2020 review in Clinical Diabetes walks through many of these reasons.

What you shouldn’t do is overlap them. The Wegovy, Zepbound and Foundayo labels all say they are not recommended together with another GLP-1 medicine. A switch means one stops and the other starts, on a date your prescriber sets.

Is there an official conversion chart from Ozempic to Mounjaro?

No. We checked the current US labels on DailyMed on 14 October 2026:

• The Mounjaro and Zepbound labels list a single starting dose, 2.5 mg once weekly, and contain no section on switching from another GLP-1.
• The Ozempic injection label starts at 0.25 mg and has no switching section either.
• Lilly’s medical information says it cannot recommend how to switch to tirzepatide, does not provide dose equivalence, and has not studied switching for weight management.

You will find conversion charts online. Some come from published clinical reviews built on glucose-lowering data from separate trials. Their own authors describe them as a starting guide or as expert opinion, not as validated conversions. A 2023 Clinical Diabetes report on drug shortages put it that way, and the 2020 review said its equivalent doses rested entirely on the authors’ opinion. That’s why no dose is suggested here: it’s a prescriber decision.

What do the labels say about switching?

The only switching instructions in US labels involve semaglutide, between its pill and shot forms:

How do prescribers usually plan a switch?

Without a label rule, prescribers fall back on a few principles from clinical reviews. These are what you can expect to discuss, not steps to follow yourself.

Timing of the first new dose

For a switch between two weekly medicines, reviews describe stopping the old one and starting the new one about a week later, on the usual day of the week. From a daily medicine, the new one usually starts the next day. The semaglutide labels follow the same pattern.

The reason is how slowly these drugs leave the body. Semaglutide has a half-life of about a week, and the Wegovy label says it stays in circulation for about 5 to 7 weeks after the last dose. Tirzepatide’s half-life is about 5 to 6 days in people with obesity; orforglipron’s is 29 to 49 hours.

You can see the shape of that tail with our GLP-1 half-life calculator, and how GLP-1 steady state works explains why levels take weeks to settle after any change.

Starting dose

The default is the new medicine’s own label starting dose, then its usual ladder, as in our GLP-1 dose escalation schedule. Some studies started higher. In SURPASS-SWITCH-2, people on stable semaglutide, dulaglutide or liraglutide went straight to tirzepatide 5 mg for 12 weeks. Lilly notes that design had no control group and doesn’t support general switching rules.

Side effects and other medicines

If the switch is because of side effects, the 2020 review suggests waiting until symptoms settle, then starting the new medicine at its lowest dose. Stomach side effects can come back after a switch; the review notes they tend to ease over time, as they often did when you first started.

If you take insulin or a sulfonylurea, those doses may need adjusting. In SURPASS-SWITCH, low glucose readings were more common after switching to tirzepatide than with dulaglutide. If you use birth control pills, the tirzepatide labels advise a backup method for 4 weeks after starting and after each increase; Foundayo’s label says 30 days.

A check-in after the switch

The 2020 review suggests reassessing within 2 to 3 months, covering dose steps, side effects, other medicines and goals.

What about switching from an injection to a pill?

For semaglutide, the Wegovy and oral semaglutide labels give the timing shown in the table. Foundayo’s label has no switching section, so there the prescriber decides.

The best evidence so far is ATTAIN-MAINTAIN (Nature Medicine, 2026). People who had lost weight on injectable semaglutide or tirzepatide switched to orforglipron or placebo for a year. From semaglutide, the pill group kept 79.3% of their earlier weight loss vs 37.6% on placebo; from tirzepatide, 74.7% vs 49.2%. The trial didn’t compare the pill with staying on the injection. For how the pills differ day to day, see our GLP-1 pills comparison.

What should you log before and after a switch?

A switch is easier to judge when you have a clear before-and-after record.

Before the switch

• Date, time and dose of your last dose of the old medicine
• Your current dose and how long you’ve been on it
• Side effects over the last few weeks, with severity
• Weight trend (weekly average) and, if you have diabetes, glucose readings
• Why you’re switching, and your other medicines, including insulin, sulfonylureas, thyroid pills and birth control

After the switch

• Date of the first new dose and every dose step
• Nausea, vomiting, constipation, diarrhea and appetite, with severity
• Fluids and meals on bad days
• Weekly weight average, compared with your pre-switch trend
• Any low glucose readings or symptoms
• Questions for your next appointment

Red flags after switching: when should you call your doctor?

Contact your doctor promptly, or seek urgent care, if you have:

• Severe stomach pain that won’t go away, with or without vomiting (possible pancreatitis)
• Vomiting or diarrhea that stops you keeping fluids down, or dizziness and very little urine
• Pain in the upper right belly, fever or yellowing skin or eyes (possible gallbladder problems)
• Swelling of the face, lips, tongue or throat, or trouble breathing
• Shakiness, sweating, confusion or readings below your target if you take insulin or a sulfonylurea
• A dose of both medicines too close together, or a double dose by mistake

Making the switch easier to follow

GLPMate keeps the record above in one place: a dose log with reminders, a side-effect log with severity, your weight trend, and an estimated medication-level chart based on the doses you log. Before your appointment, a doctor report turns it into a PDF your prescriber can review.

This article is educational only and not medical advice. Never stop, start, overlap or convert GLP-1 doses on your own; plan every switch with your prescriber.

FAQ

FAQ

What dose of Mounjaro do you start when switching from Ozempic?

The Mounjaro label lists one starting dose, 2.5 mg once weekly, and has no instructions for people coming from semaglutide. Lilly says it cannot recommend a switching method or a dose equivalence. Your prescriber chooses the first dose based on the label, your current Ozempic dose, how you tolerated it and your blood glucose.

How long should you wait between Ozempic and Mounjaro?

No label sets a gap for this switch. Clinical reviews describe starting the new weekly medicine about one week after the last dose, on your usual injection day, rather than overlapping them. Semaglutide has a half-life of about a week, so it is still in your body for weeks after the last shot; your prescriber will set the exact date.

Can you switch from Wegovy injection to the Wegovy pill?

Yes, the Wegovy label covers it. People on the 2.4 mg injection can start 25 mg tablets one week after their last injection, and people on 25 mg tablets can start the 2.4 mg injection the day after their last tablet. If 25 mg tablets aren't tolerated, the label suggests considering the 1.7 mg injection.

Do you have to start over when switching GLP-1 medications?

Often the new medicine starts low and is stepped up, because that is how its label is written and it helps limit stomach side effects. Some studies started higher, but the manufacturer says they don't support general rules. Whether you restart at the bottom or not is your prescriber's decision.